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From Miguel Angel Martin junquera <mianmarjun.mailingl...@gmail.com>
Subject Re: how can i get the column value? Need help!.. cassandra 1.28 and pig 0.11.1
Date Mon, 02 Sep 2013 11:10:12 GMT
hi:

I test this in cassandra 1.2.9 new  version and the issue still persists .

:-(




Miguel Angel Martín Junquera
Analyst Engineer.
miguelangel.martin@brainsins.com



2013/8/30 Miguel Angel Martin junquera <mianmarjun.mailinglist@gmail.com>

> I try this:
>
> *rows = LOAD
> 'cql://keyspace1/test?page_size=1&split_size=4&where_clause=age%3D30' USING
> CqlStorage();*
>
> *dump rows;*
>
> *ILLUSTRATE rows;*
>
> *describe rows;*
>
> *
> *
>
> *values2= FOREACH rows GENERATE  TOTUPLE (id) as
> (mycolumn:tuple(name,value));*
>
> *dump values2;*
>
> *describe values2;*
> *
> *
>
> But I get this results:
>
>
>
> -------------------------------------------------------------
> | rows     | id:chararray   | age:int   | title:chararray   |
> -------------------------------------------------------------
> |          | (id, 6)        | (age, 30) | (title, QA)       |
> -------------------------------------------------------------
>
> rows: {id: chararray,age: int,title: chararray}
> 2013-08-30 09:54:37,831 [main] ERROR org.apache.pig.tools.grunt.Grunt -
> ERROR 1031: Incompatable field schema: left is
> "tuple_0:tuple(mycolumn:tuple(name:bytearray,value:bytearray))", right is
> "org.apache.pig.builtin.totuple_id_1:tuple(id:chararray)"
>
>
>
>
>
> or
>
>
>
> ....
>
> *values2= FOREACH rows GENERATE  TOTUPLE (id) ;*
> *dump values2;*
> *describe values2;*
>
>
>
>
> and  the results are:
>
>
> ...
> (((id,6)))
> (((id,5)))
> values2: {org.apache.pig.builtin.totuple_id_8: (id: chararray)}
>
>
>
> Aggg!!!!!
>
>
> *
> *
>
>
>
>
> Miguel Angel Martín Junquera
> Analyst Engineer.
> miguelangel.martin@brainsins.com
>
>
>
> 2013/8/28 Miguel Angel Martin junquera <mianmarjun.mailinglist@gmail.com>
>
>> hi:
>>
>> I can not understand why the schema is  define like *"id:chararray,age:int,title:chararray"
>>  and it does not define like tuples or bag tuples,  if we have pair
>> key-values  columns*
>> *
>> *
>> *
>> *
>> *I try other time to change schema  but it does not work.*
>> *
>> *
>> *any ideas ...*
>> *
>> *
>> *perhaps, is the issue in the definition cql3 tables ?*
>> *
>> *
>> *regards*
>>
>>
>> 2013/8/28 Miguel Angel Martin junquera <mianmarjun.mailinglist@gmail.com>
>>
>>> hi all:
>>>
>>>
>>> Regards
>>>
>>> Still i can resolve this issue. .....
>>>
>>> does anybody have this issue or try to test this simple example?
>>>
>>>
>>> i am stumped I can not find a solution working.
>>>
>>> I appreciate any comment or help
>>>
>>>
>>> 2013/8/22 Miguel Angel Martin junquera <mianmarjun.mailinglist@gmail.com
>>> >
>>>
>>>> hi all:
>>>>
>>>>
>>>>
>>>>
>>>> I,m testing the new CqlStorage() with cassandra 1.28 and pig 0.11.1
>>>>
>>>>
>>>> I am using this sample data test:
>>>>
>>>>
>>>> http://frommyworkshop.blogspot.com.es/2013/07/hadoop-map-reduce-with-cassandra.html
>>>>
>>>> And I load and dump data Righ with this script:
>>>>
>>>> *rows = LOAD
>>>> 'cql://keyspace1/test?page_size=1&split_size=4&where_clause=age%3D30'
USING
>>>> CqlStorage();*
>>>> *
>>>> *
>>>> *dump rows;*
>>>> *describe rows;*
>>>> *
>>>> *
>>>>
>>>> *resutls:
>>>>
>>>> ((id,6),(age,30),(title,QA))
>>>>
>>>> ((id,5),(age,30),(title,QA))
>>>>
>>>> rows: {id: chararray,age: int,title: chararray}
>>>>
>>>>
>>>> *
>>>>
>>>>
>>>> But i can not  get  the column values
>>>>
>>>> I try to define   another schemas in Load like I used with
>>>> cassandraStorage()
>>>>
>>>>
>>>> http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Cassandra-and-Pig-how-to-get-column-values-td5641158.html
>>>>
>>>>
>>>> example:
>>>>
>>>> *rows = LOAD
>>>> 'cql://keyspace1/test?page_size=1&split_size=4&where_clause=age%3D30'
USING
>>>> CqlStorage() AS (columns: bag {T: tuple(name, value)});*
>>>>
>>>>
>>>> and I get this error:
>>>>
>>>> *2013-08-22 12:24:45,426 [main] ERROR org.apache.pig.tools.grunt.Grunt
>>>> - ERROR 1031: Incompatable schema: left is
>>>> "columns:bag{T:tuple(name:bytearray,value:bytearray)}", right is
>>>> "id:chararray,age:int,title:chararray"*
>>>>
>>>>
>>>>
>>>>
>>>> I try to use, FLATTEN, SUBSTRING, SPLIT UDF`s but i have not get good
>>>> result:
>>>>
>>>> Example:
>>>>
>>>>
>>>>    - when I flatten , I get a set of tuples like
>>>>
>>>> *(title,QA)*
>>>>
>>>> *(title,QA)*
>>>>
>>>> *2013-08-22 12:42:20,673 [main] INFO
>>>>  org.apache.pig.backend.hadoop.executionengine.util.MapRedUtil - Total
>>>> input paths to process : 1*
>>>>
>>>> *A: {title: chararray}*
>>>>
>>>>
>>>>
>>>> but i can get value QA
>>>>
>>>> Sustring only works with title
>>>>
>>>>
>>>>
>>>> example:
>>>>
>>>> *B = FOREACH A GENERATE SUBSTRING(title,2,5);*
>>>> *
>>>> *
>>>> *dump B;*
>>>> *describe B;*
>>>> *
>>>> *
>>>> *
>>>> *
>>>>
>>>> *results:*
>>>> *
>>>> *
>>>>
>>>> *(tle)*
>>>> *(tle)*
>>>> *B: {chararray}*
>>>>
>>>>
>>>>
>>>>
>>>> i try, this like ERIC LEE inthe other mail  and have the same results:
>>>>
>>>>
>>>>  Anyways, what I really what is the column value, not the name. Is
>>>> there a way to do that? I listed all of the failed attempts I made below.
>>>>
>>>>    - colnames = FOREACH cols GENERATE $1 and was told $1 was out of
>>>>    bounds.
>>>>    - casted = FOREACH cols GENERATE (tuple(chararray, chararray))$0;
>>>>    but all I got back were empty tuples
>>>>    - values = FOREACH cols GENERATE $0.$1; but I got an error telling
>>>>    me data byte array can't be casted to tuple
>>>>
>>>>
>>>> Please, I will appreciate any help
>>>>
>>>>
>>>> Regards
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>>
>>> Miguel Angel Martín Junquera
>>> Analyst Engineer.
>>> miguelangel.martin@brainsins.com
>>> Tel. / Fax: (+34) 91 485 56 66
>>> *http://www.brainsins.com*
>>> Smart eCommerce
>>> *Madrid*: http://goo.gl/4B5kv
>>>  *London*: http://goo.gl/uIXdv
>>>  *Barcelona*: http://goo.gl/NZslW
>>>
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>>>
>>
>>
>>
>> --
>>
>> Miguel Angel Martín Junquera
>> Analyst Engineer.
>> miguelangel.martin@brainsins.com
>>
>>
>

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